The invention relates to a disc brake that is particularly embodied as a fixed-caliper disc brake or floating-caliper disc brake for a vehicle, comprising a brake pad assembly with a friction pad and a pad back plate, the friction pad being engageable with a brake disc in order to achieve a braking effect, and at least one vibration-damping device with at least one additional mass arranged on a brake caliper or on a brake carrier.
Such a disc brake is known, for example, from document EP 0 380 769 B1. In a fixed-caliper disc brake described therein, additional masses are mounted on the housing in the circumferential direction such that they are positioned radially next to the brake disc. Alternatively, the additional masses can be cast directly on one of the housing parts, thus eliminating subsequent fastening. Moreover, an inwardly clamping floating-caliper disc brake is described in document EP 0 380 769 B1 in which an additional mass is fastened on a side of an arm of a substantially U-shaped brake housing facing away from the piston. In another embodiment, in addition to recesses for guiding brake shoes, additional masses are adhered to a brake carrier via an elastic adhesive layer.
Through the frictional contact between the friction pad and the brake disc, friction-induced oscillations are often introduced into the brake pad assembly, for example as a result of the so-called stick-slip effect. These friction-induced oscillations are transmitted from the brake pad assembly to adjacent components of the disc brake, particularly to the brake piston or the brake carrier. This has a negative impact particularly when the frequency of the friction-induced oscillation coincides with the natural resonant frequency of the brake pad assembly and/or of one or more of the other components of the disc brake. As a consequence of such a transmission of a friction-induced oscillation, the friction-induced oscillation leaves the disc brake as an acoustically perceptible, unpleasant sound wave (“squealing”).
The transmission of the friction-induced oscillation can be effectively suppressed if the resonant frequencies of adjacent components of the disc brake, for example of the brake pad assembly and the brake caliper, do not match. This is tantamount to a damping of the friction-induced oscillation. It is known from the prior art to influence the mass distribution in (at least a portion of) the disc brake by means of additional weights, referred to here as additional masses, for this purpose. In order to fasten such additional masses to the disc brake, in conventional disc brakes the additional masses are adhered directly to a surface of the brake carrier.